WASHINGTON — The White House on Thursday threatened to veto legislation that would keep A-10 Warthogs in Fort Smith.

The Office of Management and Budget said it is recommending that President Barack Obama veto the defense authorization bill now being debated in the Senate.

OMB expressed a number of concerns with the bill that would set military policy for the 2013 fiscal year, including a provision to block the Air Force from changing any missions assigned to the Air National Guard.

The administration "strongly objects" to the restriction, OMB said, fearing it would lead to a "hollow force" as aircraft are kept in the fleet without adequate resources to back them up.

U.S. Sen. Mark Pryor, D-Ark., denounced the White House’s veto threat and the Air Force plan to remove the A-10s from the 188th Fighter Wing and replace them with a drone mission.

"The president is wrong on this issue," he said.

U.S. Rep. Tim Griffin, R-Little Rock, said he hopes the Senate will move forward with the bill regardless of the veto threat.

"We’ve got to do this. We’ve got to fight for it. I don’t think we are left with any other choice," Griffin said.

Griffin noted that the Pentagon had failed to provide Congress with analysis or data backing up the budget justifications for the Air Guard reductions.

In February, the Air Force proposed $487 billion in spending reductions over the next decade that fell heavily on the Air National Guard. Congress responded by blocking the Air Force from making any mission changes to the Air Guard as part of a temporary budget resolution that extends into March.

The Senate defense authorization bill would extend the freeze through September, when the 2013 fiscal year ends. The bill is still being debated in the Senate.

"There are senators and congressmen on both sides of the aisle who support halting the Air Force’s restructuring proposal. I sincerely hope that the president does not veto the bill," Pryor said.

The Arkansas delegation has argued that the 188th Fighter Wing is the most cost effective and efficient of the Air Guard’s A-10 wings. They have requested budget documentation from the Pentagon to justify the proposed change in mission without success.

"Their plan is short on details, budgetary analysis, and military readiness justification," Pryor said.

The administration said it strongly objected to a number of other issues in the bill contributing to the veto threat, including proposed restrictions on the transfer of prisoners from Guantanamo Bay, restrictions on Pakistani assistance and limitations on military construction funding for Guam.